Lençóis Maranhenses National Park

White dunes roll inland from an 80-kilometre stretch of Maranhão's coast, and when the rains come the hollows between them fill with freshwater lagoons in shifting shades of blue and green. This is South America's largest dune field, lying at the meeting point of the Cerrado, Caatinga and Amazon biomes. UNESCO added Lençóis Maranhenses National Park to the World Heritage List in 2024 for coastal scenery and dune geology with few equals anywhere.